The present invention relates to assemblies useful in inflatable restraint systems.
Inflatable restraint systems are becoming the norm for passenger protection. A rudimentary system comprises of a crash sensor mounted to the vehicle frame and an air bag assembly positioned within the passenger compartment. Differing types of assemblies are used for driver side restraint systems and passenger side restraint systems. The present invention finds specific application with a passenger side air bag restraint system. Typically these assemblies will include an outer reaction can into which is received a gas generator. This can is an integrated, structurally sound member which absorbs and retransmits the air bag deployment forces to the vehicle. The can also supports the weight of the gas inflator and an air bag. An air bag is placed into the can in close proximity to the gas generator and a cover is placed about the outer can to secure the bag in its nondeployed or stored condition. FIG. 1 illustrates an examplary passenger side air bag assembly. This system also comprises a reaction can (a) that is typically mounted to or near the dash board or instrument panel of the vehicle. The can includes a partially enclosed side (b) having a plurality of perforations (c) and an opened end (d) surrounded by a flange (e). During assembly a gas generator (f) is secured to the can (a), thereafter an air bag (g) is mounted within the can in a manner to receive the gas generated by the gas generator (f). A cover (h) (shown in phantom line), typically of a breakable plastic material, is secured across the open end of the can i.e., on or about the flange (e).
The assembly shown in FIG. 1 must be inserted within the vehicle during its manufacture. A deficiency inherent to this type of assembly is that the gas generator (f) must be inserted into the reaction can (a) prior to the placement of the air bag (g). As such at an early state of the fabrication of the assembly the gas generator becomes an integral portion thereof. The assembly is inspected, packaged, and transported with the gas generator in place thereby subjecting the gas generator to mishandling, vibration, impact, etc. A gas generator which is always a part of a completed assembly presents an increased potential safety hazard since there exists a greater possibility that during the transportation, testing, etc. of the assembly an inadvertent activation of the gas generator and deployment of the air bag may occur.
FIG. 2 illustrates another prior art air bag assembly comprising an outer or reaction can (j) having sidewalls (not shown in FIG. 2). The outer can is adapted to fit within the dashboard or instrument panel generally shown as (k). Fitted within the can is a dual air bag (l). Upon deployment (see phanthom lines) the dual air bag (l) generates a first air bag portion 1' to envelope the occupant and a second air bag 1" which functions as a knee bolster. The dual air bag (l) is secured within the can by an exterior cover (m). Ends (n) of the air bag were first sewn together at location (o) forming a pouch into which an inner can (p) was inserted. Bolts (q) of the inner can (p) extended through openings in the sewn together ends (n) of the air bag and were fastened to a portion of the outer can (j). A gas generator (r) as inserted into the inner can through openings in the sidewalls of the outer can and secured thereto by bolts.
It is the object of the present invention to provide an air bag assembly in which the gas generator may be inserted at times after the insertion of an air bag. A further object of the present invention is to provide an improved packaging methodology for securing an air bag within an assembly in its predeployment condition. It is an object of the invention to provide an assembly in which a reaction can is an optional element. A further object of the present invention is to provide an assembly capable of being mounted directly to the vehicle.
Accordingly a first embodiment of the invention comprises: an assembly comprising: a hollow cylindrical member or can including an opening into which generator means may be inserted. The generator means is of the type responsive to a control signal, for generating gas to inflate an air bag means. The assemble further includes air bag means, responsive to the gas, for protecting, when activated, an occupant of a vehicle, comprising an inflatable bag or sack, disposed in a compacted or stored condition, during periods prior to deployment, proximate a side of the cylindrical member containing at least one aperture. The inflatable bag, includes an open end disposed about the cylindrical member to receive the gas and includes relatively opposing flaps extending from proximate the open end and adapted to envelop the cylindrical member. The flaps, proximate a side of the cylindrical member, away from the at least one aperture, disposed in an overlapping, condition, one to the other. The assembly also includes means for maintaining the inflatable bag in its compacted or stored condition prior to inflation. The cylinder may be attached to a structural reaction can, a non-structural cover or shield or directly to a cavity formed within the instrument panel of a vehicle. The gas generator is thereafter fitted to the reaction can etc. In other embodiments a means for radially securing a gas generator is shown. In these emboidments the gas generator and related components may be directly attached to a structure avoiding the need to use a structural reaction can. Such means includes: a bent loop type of clamp, a flat band, radially extending studs or brackets. The air bag may be positioned in an enveloping manner directly about the gas generator or about an intermediate cylindrical member.
Many other objects and purposes of the invention will be clear from the following detailed description of the drawings.